Self-propelling and steering attachment for a wheel-chair

Abstract

A self-propelling and steering attachment for a wheel-chair which can be installed and removed by the user while remaining seated in the wheel-chair and which comprises a sleeve, a steering post rotatably supported by the sleeve, a ground-engaging steering and propelling wheel carried by the lower end of the steering post, a crank mechanism carried by the top end of the steering post, a power transmission connecting the crank and the steering and propelling wheel, a framework which is quickly connectable to, and disconnectable from, the front frame portion of the wheel-chair, and a pair of superposed longitudinally-extending bars interconnecting the framework and the sleeve. The upper bar is rigid with the sleeve at one end and pivots relative to the framework at the other end. The lower bar is pivotally connected to the sleeve and to the framework and is extensible and retractable, being provided with a locking pin to lock this bar to a retracted, adjusted length. For installation of the attachment, the user first rigidly connects the framework to the wheel-chair front frame portion, while the locking pin is removed, then he pushes forwardly on the crank mechanism or on the upper portion of the steering post to cause the latter to attain a more upright position, therefore causing the front swivel wheels of the wheel-chair to raise off the ground. With this movement, the lower bar has retracted and the user then inserts the locking pin to lock the lower bar in retracted position.

What I claim is: 
     
       1. A self-propelling and steering attachment for a wheel-chair of the type having a frame, rear larger diameter wheels supporting said frame and front smaller diameter swivel wheels supporting said frame at the front frame portion thereof, said attachment comprising a front sleeve, a steering post rotatably supported in said sleeve, a ground-engaging steering and propelling wheel carried by the bottom of said steering post, drive means for said steering and propelling wheel, a rear framework, means on said framework to rigidly connect and disconnect the same to and from the front frame portion of said wheel-chair, and two superposed bars extending longitudinally forwardly from said rear framework and interconnecting the latter and said sleeve, one of said bars being extensible and retractable and pivotally connected to said rear framework and to said sleeve for pivotal movement about horizontal transverse axes relative to said wheel-chair, and the other of said bars being rigidly secured to one of said framework and of said sleeve and pivotally connected to the other of said framework and of said sleeve for pivotal movement about a horizontal transverse axis relative to said wheel-chair, and means to lock said extensible and retractable bar to an adjusted length, whereby a wheel-chair user, while seated in the wheel-chair, can secure said framework to said wheel-chair front frame portion when said locking means are in released position and while said front swivel wheels of the wheel-chair rest on a support surface, and then the user can lift said swivel wheels off the ground by pushing forwardly of said steering post to cause the same to take more vertical attitude, thereby causing a change of length of said extensible and retractable bar and then locking the latter in its final position with the swivel wheels remaining raised off the supporting surface and the wheel-chair resting on said supporting surface only by the rear large diameter wheels and the steering and propelling wheel. 
     
     
       2. A self-propelling and steering attachment as claimed in claim 1, wherein said other of said bars is rigidly connected to said sleeve and pivotally connected to said rear framework. 
     
     
       3. A self-propelling and steering attachment as claimed in claim 2, wherein said other of said bars is the upper one and said extensible and retractable bar is the lower one. 
     
     
       4. A self-propelling and steering attachment as claimed in claim 1, 2 or 3, wherein said rear framework consists of an elongated frame including top and bottom horizontal members extending perpendicularly to, and connected to, said two superposed bars, respectively, each of said top and bottom horizontal members being made of telescopically-engaged sections, each end section of each member having endwise protruding lugs at their outer ends engageable with the front frame portion of said wheel-chair and manually-operated toggle lever means to move said telescopic sections between a retracted position clearing said front frame portion, and an extended position with the lugs firmly engaging said front frame portion of said wheel-chair, and uprights rigidly interconnecting the telescopic upper and lower sections, respectively. 
     
     
       5. A self-propelling and steering attachment as claimed in claim 1, 2 or 3, wherein the wheel-chair front frame portion includes top and bottom lateral, horizontally-extending members on each side of the chair, and uprights rigidly interconnecting said top and bottom members and said framework includes a generally rectangular frame adapted to extend between the two uprights of the wheel-chair frame and including top and bottom horizontal members consisting of three telescopic sections, namely two end sections and an intermediate section, said intermediate section being rigidly connected at right angles to the upper bar and being rotatably mounted within the two end sections, one section of the retractable and extensible bar being rigidly secured at right angles to the intermediate section of the lower horizontal member, uprights rigidly interconnecting the upper and lower end sections two by two, the end sections of the upper horizontal member being provided with endwise protruding lugs adapted to have a sliding fit on each side of the uprights of the wheel-chair, the end sections of the lower horizontal member being provided with rigidly secured, endwise projecting lugs adapted to engage over the lower lateral horizontal side members of the wheel-chair frame rearwardly of the uprights and lateral lugs engageable with and having a sliding fit with the front of the uprights of the wheel-chair, and a manually-operated toggle lever system interconnecting the two uprights of the framework to extend a pair of upper and lower end sections longitudinally with respect to the other pair of lower and upper end sections, so as to cause engagement of the lugs with the respective uprights and with the lower horizontal member of the wheel-chair frame. 
     
     
       6. A self-propelling and steering attachment as claimed in claim 1, wherein said drive means include a crank means carried by the top of said steering post, and a power transmission means including means to change the speed ratio between said crank means and said steering and propelling wheel. 
     
     
       7. A self-propelling and steering attachment as claimed in claim 1, 2 or 3, further including spring means biasing said steering and propelling wheel in a position in alignment with the central transverse plane of the wheel-chair fitted with the attachment. 
     
     
       8. A self-propelling and steering attachment as claimed in claim 6, wherein said crank mechanism is supported at the upper end of said steering post for adjustable positioning thereof to suit users having different arm lengths. 
     
     
       9. A self-propelling and steering attachment as claimed in claim 6, further including a support arm adjustably pivotally secured at one end to the upper end of said steering post and carrying said crank means at its other end.